In Morgan et al copending U.S. patent application Ser. No. 539,121, now U.S. Pat. No. 4,547,028, there is disclosed an electrical clip-like connector of low profile that is attachable to an electrical device such as an integrated circuit package for connecting the conductors of an electrical cable with the leads of such device. Because of its low profile, the connector may be used in situ in confined environments. The connector comprises an electrical cable of the flat or ribbon type including plural electrical conductors and a pair of low height clip bodies molded to the cable. Each clip body includes therein plural electrical contacts each having an exposed contacting portion for engaging a respective lead of the electrical device and a mounting portion about which the clip body is molded and which is electrically connected to a respective conductor of the cable at a portion thereof from which the cable insulation has been removed. The connector also comprises a connecting mechanism for mechanically connecting the pair of bodies with respect to each other for mounting of the connector to the electrical device with respective electrical contacts engaged with respective leads of the device. Such connecting mechanism may include parallel leaf springs at respective lateral ends of the connector and to which the clip bodies are also molded.
Manufacture of such low profile connector was accomplished by first soldering the contacts to respective conductors of the cable at portions of the conductors from which the cable insulation had been removed to form a cable/contact sub-assembly. The sub-assembly was then placed along with the leaf springs into the cavity of a mold for molding of the clip bodies about respective portions of the cable, portions of the leaf springs, and portions of the contacts with the soldered junctions being fully encapsulated by the clip bodies to provide a hermetic seal about the soldered junctions. After the mold was closed, molten plastic material from which the clip bodies were formed was introduced into the mold cavity to fill the same, this involving flow of the molten plastic material around the cable to provide clip body portions both above and below the cable.
In such prior manufacturing procedure, there was a problem of cable shifting when the plastic clip bodies were molded around the cable. That is, forced flow of molten plastic material engaging a planar surface of the cable in the mold cavity would tend to shift or displace the cable from its desired intermediate spaced position between top and bottom surfaces of the mold cavity. Consequently, the cable would not be located properly in the molded clip bodies and this cable shifting problem necessitated the scrapping of a considerable number of the connectors which added to the overall cost of manufacturing the connectors.
The cable shifting problem was solved in copending U.S. patent application Ser. No. 681,362, now U.S. Pat. No. 4,679,870 by the use of separately molded plastic caps which became integral parts of respective clip bodies upon subsequent molding of respective balance forming portions of the clip bodies to the electrical cable. Each cap was in the form of a planar strip of plastic or other suitable material provided with plural tapered holes spaced along its length. The cap was loaded into the test clip mold along with the cable/contact sub-assembly with the cap in juxtaposition with the side of the cable opposite the contacts. After the mold was closed, molten plastic material was introduced into the mold cavity to form the balance of the clip body, the molten material flowing up through an insulation removed area of the cable around the soldered junctions and into the tapered holes of the cap which locked the cap to the thusly molded balance forming portion of the clip body. In operation, the cap formed what may be called an essentially rigid backstop for the cable which prevented shifting of the cable as the molten plastic was forced into the mold cavity. The cap also became an integral part of the clip body forming the upper center portion of the clip body while the subsequently molded balance forming body portion formed the lower and end portions of the clip body. Through elimination of the cable shifting problem, there was provided a clip-like connector of greater uniformity, there being assurance that the cable was properly located in each clip body, i.e., the electrically non-conductive support portion of the connector.
Clip connectors of the foregoing low profile type have been used for high speed signal testing purposes which often require the use of high speed signal transmission line cable. In such cable, the signal conductors were bounded by ground conductors for signal isolation purposes and provision was made in the connectors for connecting the ground isolation conductors to ground potential at the connector/cable interface.
Such clip connectors also have been or can be used for purposes other than testing, such as signal injecting, signal reading, device connection or the like. By way of specific example, such clip connectors have been used to connect an add-on fixed disc drive to a closed architecture microcomputer. For this purpose, the connecting cable leading from the drive's controller would be provided with a clip connector which was attachable directly to the computer's microprocessor for connecting the conductors of the cable to the leads of the microprocessor. Although the connecting cable heretofore utilized in this application was of the high speed signal transmission line type, a cable without ground isolation could be used with satisfactory results, such as flat PVC cable including only signal conductors.
The signal conductors of flat PVC cable could be connected to the connector's contacts by soldered junctions and the soldered junctions sealed by the clip bodies molded thereabout in the above-indicated manner. The soldering procedure, however, is relatively difficult to perform in relation to the insulation displacement technique heretofore used to connect simultaneously each of plural conductors of a cable to respective contacts in other types of electrical connectors. Typically, these other types of electrical connectors include multiple housing parts between which the cable is clamped, and usually before or during clamping the plural contacts of the connector puncture the electrical insulation of the cable to connect with respective conductors of the cable. An example of a low profile, insulation displacement connector which is clip-like attachable to an integrated circuit package is shown in U.S. Pat. No. 4,190,311, but such connector has inadequate protection against the problems associated with moisture and oxygen at the electrical junctions, e.g., corrosion and oxidation which degrade connector performance. The latter problems were previously addressed in Venaleck U.S. Pat. No. 4,030,799, but the connector illustrated in this patent was not designed for clip-like attachment to an electrical device such as an integrated circuit package. Although it would be desirable to use an insulation displacement or similar technique to effect electrical connections in a low profile clip connector of the general type shown in the above-noted copending patent applications, the cable type permitting, and also to mold the clip bodies about the thusly formed electrical junctions, such heretofore has not been attempted or accomplished.